1. Field
Various embodiments of the present invention relate to a semiconductor device, and more particularly, to a semiconductor device including memory cells.
2. Discussion of Related Art
A read operation is performed to read data stored in memory cells of a semiconductor device. When the threshold voltage distribution of the memory cells changes, the number of error bits included in the data read from the memory cells increases. Therefore, the read voltage applied to the memory cells during read operations needs to be changed.